The present invention relates to a forceps unit for an endoscope to be inserted into an instrument-inserting channel of an endoscope and used for blood stanching, collecting tissue samples, etc.
A forceps unit for an endoscope is generally formed by swaging and fixing a support shaft (rotatably supporting a pair of forceps end pieces) to an end support frame provided to the distal end of a flexible sheath so that the pair of forceps end pieces rotatable around the support shaft will open and close like the beak of a bird when operating wires, placed inside the flexible sheath to be reciprocable in the direction of the axis of the flexible sheath, are operated back and forth.
In actual use of such a forceps unit for an endoscope, there are cases where it is necessary to squirt cleaning liquid onto mucous membrane to wash blood or unclean liquid away, squirt coloring liquid onto mucous membrane to easily discriminate between normal membrane and abnormal membrane, etc. before the intended blood stanching, collecting tissue samples, etc.
To meet the requirements, there have been proposed forceps units for endoscopes capable of discharging cleaning liquid, coloring liquid, etc. from the tip of the flexible sheath by using the space inside the flexible sheath as a liquid feed channel. An example of such a forceps unit is disclosed in each of Japanese Patent Publication No. HEI06-98140, Japanese Patent Provisional Publication No. HEI 04-146741, and Japanese Patent Provisional Publication No. 2001-327512.